Process for isolating levulose as the lime levulate



Aug. 21, 1934. R. M. HlXON ET AL PROCESS FOR ISOLATING LEVULOSE AS THE LIME LEVULATE Filed July 50, 1931 2 Sheets-Sheet 1 INVENTORS. R.M.H1xow JHMCGLUMPHY w Aug. 21, 1934. R. M. HIXON ET AL 1,970,605

PROCESS FOR ISOLATING LEVULOSE AS THE LIME LEVULATE V Filed July 30, 1931 2 Sheets-Sheet 2 INVENTORS. RMHDwN w Jfi McGLuMPHr w JMEzcru smfln. g JhZBUcHANAN Patented Aug. 21, 1934 OFFICE PROCESS FOR. rsom'rmc LsvULosE as THE LIME LEVULATE Ralph Malcolm Hixon, James Harvey McGlum- 'phy, Jack Waldo Eichinger, Jr., and John Hall Buchanan, Ames, Iowa, assignors to Iowa State College of Agriculture and Mechanic Arts, Ames, Iowa, a corporation of Iowa Application July ,30, 1931, Serial No. 554,082

8 Claims.

fixed low temperature as has heretofore been the case.

A still further objectof this invention is to provide a process for the isolating of levulose as the lime levulate in which the precipitation of the lime levulate is rapid and convenient.

A still further object of our invention is to provide a process for isolating levulose'as the lime levulate which leaves the precipitated lime levulate in a granular form, which may be washed sufliciently free from impurities so that the regenerated levulose will crystallize immediately from the resulting syrup when seeded.

These and other objects will be apparent to those skilled in the art.

Our invention consists in the method hereinafter set forth, pointed out in our claims and illustrated in the accompanying drawings, in which: 7

Fig. 1 is a diagrammatical cross sectional view of a satisfactory arrangement of apparatus which may be utilized for the formation of lime levulate.

Fig. 2 is a side sectional view of the method of raising or lowering an over-flow pipe.

Fig. 3 is a cross sectional view, taken on line 3-3 of Fig. 1.

Fig, 4 is a cross'sectional view of a portion of the lime suspension kettle showing another method of raising or lowering the over-flow pipe.

Fig. 5 is a cross sectional view taken online 5-5 of Fig. 4.

This invention relates to a process for isolating levulose as the .lime levulate. The isolation of levulose as the lime levulate has generally been considered the most practical method of preparing levulose. Due to the fact that heretofore it has been diiiicult to precipitate the lime levulate because of the low temperature in which this processing must be done, this method has never been commercialized. Heretofore it has been necessary to precipitate the lime levulate at a temperature of between minus five degrees centigrade to plus five degrees centigrade andthen to filter the gelatinous precipitate so obtained. It has been found almost impossible to wash this gelatinous precipitate sufliciently free from impurities that crystallization of the regenerated levulose can be accomplished directly from water.

We have discovered after extensive experiments that if a levulose solution and a lime suspension .are allowed to flow slowly in the correct proportions into a sufliciently large volume of seed and stirred efilciently, that a granular and easily filterable precipitate of lime levulate results.

The numeral 10 designates a kettle for containing a levulose solution having therein a float 11, which rests on top of the levulose solution and to which is attached a rope or the like 12. The

rope 12 passes over a pulley wheel; 13 which is rotatably mounted on a suitable rack or the like. The numeral 14 designates a large pulley wheel pivotally mounted on a suitable rack. At the end of the rope 12, after it has passed over the pulley wheel 14 is a weight 15.

The numeral 16 designates a lime suspension kettle having rotatably mounted at its center a shaft 17 to which is secured the stirring blades 18 and which may be rotated by a suitable means. The numeral 19 designates a rack secured to the side of the lime suspension kettle having a slot 20.

The numeral 21 designates a flexible hose which is slidably mounted in the slot 20 by the ferrule 22. Secured to this ferrule 22 is a rope or the like 23 which passes over a pulley wheel 24 and thence .securedto a pulley wheel 25, which is secured to the large pulley wheel 14, as shown in the drawings. The numeral 26 designates a pipe having one end in communication with the flexible hose 21 and having its otherv end in communication with the lower side of the lower end portion of a precipitating kettle 2'7. The precipitating kettle 27 has pivotally mounted in its center a shaft 28, having secured to its lower end portion a propeller blade 29 to facilitate the stirring of the suspension. The shaft 28 may be rotated by any suitable means. s

The numeral 30 designates a pipe or the like communicating with the inside of the levulose solution kettle 10 and with the precipitating kettle 27 and having interimposed therein a valve 31 for controlling the amount of levulose solution entering the precipitating kettle. Near the top of the precipitating kettle 27 is a pipe 32, which allows 11,910,605: UNITED STATES-PATENT the solution, after it has reacted, to flow into a storage tank 33. In the modified form of construction shown in ,Fig. 4 and Fig. 5 for lowering and raising the hose 21 we have used the numeral 34 to designate a guide secured to the side of the lime suspension kettle to allow an over-flow cup 35 to travel up and down as required, by having integrally formed on this over-flow cup a T-shape'd member 36, which rides in the slot formed by the guide 34. The numeral 37 designates a cross member in the over-flow cup 35 to which is secured the rope 23. The cup 35 is actuated by the same means as is the ferrule 22. The reaction kettle 2'7 and the storage kettle 33 may be jacketed if temperature control is desired.

It will be seen from the foregoing that the height of thelevulose solution in the kettle 10 will control the amount of over-flow from the lime suspension kettle 16, through the flexible hose 21, the pipe 26 and into the precipitating kettle 27. As the float 11 is lowered, due to the drawing out of the levulose solution, it will, through the medium of the rope 12, rotate: the pulley wheels 13 and 14. As the pulley wheel '14 revolves 1t w n cause the rope 23, secured to the pulley wheel 25 to be let out, thereby lowering the end of the overflow hose.

The amount of levulose solution entering the precipitating kettle 27 is controlled by the valve 31.

Both the sugar solution and the lime suspension enter the precipitating kettle'Z'l when they react to form the lime levulate in the presence of a predominating quantity of seed, whichoifers a large area for crystal growth with resulting granular nature of the precipitate and its ease of filtration.

As the reactants are added, the suspension of lime levulate over-flows from the precipitating kettle 27, through the over-flow pipe 32, to a stor-' age tank 33 or to a continuous filter.

As an example of this process, clarified and hydrolyzed Jerusalem artichoke extract containing ten percent solids and a suspension of hydrated lime in the ratio of .one liter of extract to two hundred cubic centimeters of lime were allowed to flow slowly into a vessel or precipitating kettle in whichthey were kept stirred. The reactants were introduced into the bottom of the container and the lime levulate suspension allowed to over; flow at the top of the container. After the procedure had become continuous filter cakes .of one half inch thickness were deposited upon filters in one and one-half minutes. This precipitate is of such a granular nature that it can be easily handled and washed on the various types of continuous filters.

Another method for the formation of lime levulate is to allow a quantity of levulose solution to flow slowly into the required amount of lime suspension to give a slight excess over that suflicient for precipitating the lime levulate. This method is a suitable process for preparing a'volume of lime levulate to serve as seed in starting the first mentioned continuous method.

When the lime levulate prepared by either of theabove methods was converted to free levulose, syrups "of such a high degree of purity were obtained that spontaneous crystallization would take place from syrups of eighty-six percent solids within twenty-four hours. When such syrups were seeded at fifty degrees centigrade and the temperature dropped slowly to twenty-five degrees centigrade at the rate of one degree per hour, granular levulose resulted, about two pounds of white crystalline levulose were obtained from six pounds of syrup. These examples are illustrative of the principle, many variations being possible.

We claim as our invention:

, 1. A process for isolating levulose in the form of a lime-levulate suspension comprising the following steps: introducing a lime suspension and a levulose-containing solution into a vessel and in the presence of a large volume of seed, agitating the combined matter in the vessel, and

allowing the resultant lime-levulate suspension to of a lime-levulate suspension which comprises the following steps: introducing an agitated lime suspension into a vessel, introducing a levulosecontaining solution into the said vessel and in the presence of a large volume of seed, agitating the combined matter in the vessel, and allowing the resultant lime-levulate suspension to pass from the vessel.

3. A process for isolating levulose in the form of a lime-levulate suspension which comprises introducing an agitated lime suspension into a vessel, introducing a levulose-containing solution into the said vessel, and in the presence of a large volume of seed, agitating the combined matter in the vessel, and allowing the resultant limelevulate suspension to pass from the vessel at a temperaturesubstantially above five degrees centigrade. c

4. A process for isolating levulose in the form of a lime-levulate suspension comprising the following steps: introducing a lime suspension and a levulose-containing solution into a vessel and in the presence of a large volume of seed, agitating the combined matter in the vessel, and allowing the resultant lime-levulate suspension to pass from the vessel, the lime suspension and the solution being introduced into the vessel near the bottom thereof, and the resulant suspension being passed out of the vessel remote from the bottom thereof.

5. A process for isolating levulose in the form of a lime-levulate suspension which comprises tion being introduced into the vessel near the,

bottom thereof, and the resultant suspension being passed out of the vessel remote from the bottom thereof.

6. A process for isolating levulose in the form of a lime-levulate suspension which comprises introducing an agitated lime suspension into a vessel, introducing a levulose-containing solution into the said vessel, and in the presence of a large volume of seed, agitating the combined matter in the vessel, and allowing the resultant limelevulate suspension to pass from the vessel at a temperature substantially above five degrees centigrade, the lime suspension and the solution being introduced into the vessel near the bottom thereof, and the resultant suspension being passed out of the vessel remote from the bottom thereof.

7. A process for isolating levulose in the form of a lime-levulate suspension which includes the step of separately introducing a lime suspension and a levulose-containing solution to a single large batch of seed.

8. A process for isolating levulose in the form of a lime-levulate suspension which includes the step of separately introducing a lime suspension and a levulose-containing solution to a single large batch of seed, at a temperature substantially above 5 oentigrade.

RALPH MALCOLIVI HIXON. JANIES HARVEY MCGLUNIPHY. JACK WALDO EICHINGER, JR. JOHN HALL IBUCI-IANAN. 

